Re: [PATCH] kernel/watchdog: fix spurious hard lockups
From: Prarit Bhargava
Date: Tue Jun 20 2017 - 20:12:13 EST
On 06/20/2017 07:00 PM, Andi Kleen wrote:
> On Tue, Jun 20, 2017 at 06:34:23PM -0400, Prarit Bhargava wrote:
>> On 06/20/2017 05:33 PM, kan.liang@xxxxxxxxx wrote:
>>> From: Kan Liang <Kan.liang@xxxxxxxxx>
>>> Some users reported spurious NMI watchdog timeouts.
>>> We now have more and more systems where the Turbo range is wide enough
>>> that the NMI watchdog expires faster than the soft watchdog timer that
>>> updates the interrupt tick the NMI watchdog relies on.
>> Hmm ... odd that I haven't seen this. We're running a pretty wide
>> variety of systems here. Do you have a reproducer? I'd like to see
>> this occur on production HW.
> It only happens on a few specific CPU SKUs with a very wide Turbo range.
> Reproducer is typically some stress workload that turbos very high.
So stress the single Turbo Max core? Or any core?